Problem: Simplify the following expression: $x = \dfrac{t}{2} - \dfrac{t}{6}$
Explanation: In order to subtract expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $2$ and $6$ $\lcm(2, 6) = 6$ $ x = \dfrac{3}{3} \cdot \dfrac{t}{2} - \dfrac{1}{1} \cdot \dfrac{t}{6} $ $x = \dfrac{3t}{6} - \dfrac{t}{6}$ $x = \dfrac{3t -t}{6}$ $x = \dfrac{2t}{6}$ Simplify the expression by dividing the numerator and denominator by 2: $x = \dfrac{t}{3}$